<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        div{
            width: 300px;
            height: 150px;
            /* margin调整元素边框与边框之间的距离(外边距) */
            margin: 20px;
        }
        .c1{
            border:solid;
        }
        .c2{
            border:5px solid red;
        }
        .c3{
            border: 5px dashed green;
        }
        .c4{
            border: 5px dotted blue;
        }
        .c5{
            border:5px double orange;
        }
    </style>
</head>
<body>
        <div class="c1"></div>
        <div class="c2"></div>
        <div class="c3"></div>
        <div class="c4"></div>
        <div class="c5"></div>
</body>
</html>